Your technique advocates leaving the
air bubble in
and relying on your eyesight , judgment, good luck to not inject the
bubble into your body. If the bubble happens to inject into a small vein....goggle up , "air bubble", embolism and stroke to see if this "money saving" tip is worth the potential costs. And if the air bubble gets injected into your fatty sub-Q along with the rest of the medicine then you significantly raise the likelihood of an infected abscess developing.